Thinning of gate insulating film has been promoted in a MISFET (Metal Insulator Semiconductor Field Effect Transistor) element in order to ensure sufficient gate capacitance, however, as a result, the problem of increase of a leak current between a gate and a substrate due to tunneling arises.
Thus, a technique is used in which generation of tunneling is suppressed by using a high-dielectric constant material for a material of a gate insulating film. On the other hand, it is known that fixed charge is generated in a high-dielectric constant gate insulating film, which leads to shift threshold voltage. The technique, for example, is disclosed in JP-A 2008-010611.